全文获取类型
收费全文 | 23297篇 |
免费 | 1735篇 |
国内免费 | 542篇 |
专业分类
耳鼻咽喉 | 253篇 |
儿科学 | 1594篇 |
妇产科学 | 253篇 |
基础医学 | 2619篇 |
口腔科学 | 102篇 |
临床医学 | 3484篇 |
内科学 | 4159篇 |
皮肤病学 | 112篇 |
神经病学 | 780篇 |
特种医学 | 624篇 |
外科学 | 1381篇 |
综合类 | 3713篇 |
现状与发展 | 6篇 |
预防医学 | 3250篇 |
眼科学 | 50篇 |
药学 | 2213篇 |
43篇 | |
中国医学 | 723篇 |
肿瘤学 | 215篇 |
出版年
2024年 | 70篇 |
2023年 | 451篇 |
2022年 | 1122篇 |
2021年 | 1598篇 |
2020年 | 1244篇 |
2019年 | 718篇 |
2018年 | 665篇 |
2017年 | 788篇 |
2016年 | 876篇 |
2015年 | 797篇 |
2014年 | 1283篇 |
2013年 | 1554篇 |
2012年 | 1196篇 |
2011年 | 1204篇 |
2010年 | 997篇 |
2009年 | 933篇 |
2008年 | 831篇 |
2007年 | 980篇 |
2006年 | 1012篇 |
2005年 | 947篇 |
2004年 | 1000篇 |
2003年 | 1084篇 |
2002年 | 448篇 |
2001年 | 432篇 |
2000年 | 315篇 |
1999年 | 292篇 |
1998年 | 283篇 |
1997年 | 262篇 |
1996年 | 214篇 |
1995年 | 215篇 |
1994年 | 187篇 |
1993年 | 182篇 |
1992年 | 187篇 |
1991年 | 140篇 |
1990年 | 121篇 |
1989年 | 115篇 |
1988年 | 112篇 |
1987年 | 103篇 |
1986年 | 82篇 |
1985年 | 129篇 |
1984年 | 82篇 |
1983年 | 55篇 |
1982年 | 56篇 |
1981年 | 43篇 |
1980年 | 38篇 |
1979年 | 29篇 |
1978年 | 31篇 |
1977年 | 20篇 |
1976年 | 15篇 |
1974年 | 9篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
31.
Electrode Configurations for a Respiratory Impedance Measurement Suitable for Rate Responsive Pacing 总被引:2,自引:0,他引:2
TIBOR NAPPHOLTZ HARRY VALENTA JAMES MALONEY TONY SIMMONS 《Pacing and clinical electrophysiology : PACE》1986,9(6):960-964
A rate responsive cardiac pacemaker will benefit the patient only if the input parameter is a reliable indicator of exercise, Part of the reliability is dependent upon selection of the best physiological parameter and part is dependent upon the measurement technique. Twenty-six patients have been studied in order to ascertain the best measurement configuration for an intravascular impedance respiratory monitor. Four electrode configurations have been examined at rest and during exercise. The results have been compared using measures of sensitivity and specificity. The ideal configuration requires that a current field be established between the right ventricular blood and the pacemaker case. And, that voltage sensing be done between an electrode in the SVC and the pacemaker case. 相似文献
32.
Mortality in police and firefighters in New Jersey 总被引:5,自引:0,他引:5
A proportionate mortality study of police and firefighters in New Jersey was conducted using the records of a comprehensive retirement system. Three reference populations were used: U.S. general population, New Jersey general population, and police as a reference group for the firefighters. Overall neither group differed from the New Jersey male population in the cause of death. Analyses by latency showed an increase in skin cancer and cirrhosis in firefighters and cirrhosis in police. With increased time from first employment, an inverse association was found between heart disease and time of first exposure. This was reflected in statistically significant increased proportionate mortality rates (PMR) for arteriosclerotic heart disease (ASHD) (ICD 410-414) for both working police (PMR = 1.15) and firefighters (PMR = 1.2). Retired police and firefighters had PMRs of 0.96 and 0.98, respectively. Firefighters had a significant increase in nonmalignant respiratory disease (PMR = 1.98) and leukemia (PMR = 2.76) when the police were used as a reference group. Potential causes of the above findings are discussed. 相似文献
33.
34.
Effect of moderate exercise on salivary immunoglobulin A and infection risk in humans 总被引:3,自引:0,他引:3
Klentrou P Cieslak T MacNeil M Vintinner A Plyley M 《European journal of applied physiology》2002,87(2):153-158
The incidence of upper respiratory tract infections (URTI) and salivary immunoglobulin A concentrations [IgAs] of nine individuals were examined during 12 weeks of moderate exercise training, and compared to ten sedentary controls.
Changes in maximal oxygen uptake were assessed at initial, mid-point and final evaluations (T1–3), while changes in [IgAs] and salivary immunoglobulin concentration-salivary albumin concentration ratio ([IgAs]:[Albs]) were monitored at T1 and T3. During the 12 week period, symptoms of URTI were self-recorded daily. During the period of
training the level of fitness significantly increased (P<0.05) in the exercise group. The number of days recording symptoms of influenza, but not of cold, and total light URTI symptoms was significantly reduced in the exercise group during the last weeks of training. A significant increase in
[IgAs] and in [IgAs]:[Albs] was found in the exercise group after training. Both [IgAs] and [IgAs]:[Albs] were significantly related to the number of days showing symptoms of influenza (P<0.01) and the total number of days of sickness (P<0.05). These data provide quantitative support for the belief that regular, moderate exercise results in an increased [IgAs] at rest and [IgAs]:[Albs], which may contribute to a decreased risk of infection.
Electronic Publication 相似文献
35.
Ultrastructural abnormalities of spermatozoa and respiratory cilia have been reported in a male patient with Kartagener's syndrome and infertility.
In this patient both respiratory cilia and sperm tails showed defects in radial spokes and dynein arms. Such defects are heretofore undescribed in the same subject with immotile cilia syndrome.
Absence of both inner and outer dynein arms and absence of the inner dynein arms only were detected in spermatozoa and in respiratory tract cilia, respectively. Moreover, total absence of axoneme was seen in several sperm tails from this patient.
The possibility that the features described are of genetic origin is discussed. 相似文献
In this patient both respiratory cilia and sperm tails showed defects in radial spokes and dynein arms. Such defects are heretofore undescribed in the same subject with immotile cilia syndrome.
Absence of both inner and outer dynein arms and absence of the inner dynein arms only were detected in spermatozoa and in respiratory tract cilia, respectively. Moreover, total absence of axoneme was seen in several sperm tails from this patient.
The possibility that the features described are of genetic origin is discussed. 相似文献
36.
Ruth Tachezy Eva Hamsikova Jaroslav Valvoda Marc Van Ranst Jan Betka Robert D. Burk Vladimir Vonka 《Journal of medical virology》1994,42(1):52-59
Recurrent respiratory papillomatosis (RRP) is the most common benign tumour of the larynx, affecting both children and adults. We present a series of 25 patients, including 10 cases of juvenile multiple, 8 cases of adult solitary, and 7 cases of adult multiple RRP. Biopsy tissue from each patient was screened by Southern blot hybridization and polymerase chain reaction for the presence of human papillomavirus (HPV) DNA. Sera from patients and age- and sex-matched controls were tested for the presence of HPV-specific antibodies using a synthetic pep-tide derived from the minor capsid protein (L2) of HPV 6/11. By Southern blot hybridization and/or polymerase chain reaction, biopsies from all patients were positive for HPV 6/11 DNA. There was no difference in antibody response between cases and controls. Female cases and controls had significantly higher antibody titers than male subjects. A correlation was observed between the HPV-specific antibody level and the number of surgery-necessitating recurrences. © 1994 Wiiey-Liss, Inc. 相似文献
37.
Monoclonal antibodies against human granulocytes and myeloid differentiation antigens 总被引:4,自引:0,他引:4
Patrice Mannoni Anna Janowska-Wieczorek A. Robert Turner Locksley McGann Jean-Michael Turc 《Human immunology》1982,5(4):309-323
Monoclonal antibodies (MCA) were obtained by immunizing BALB/c mice with 99% pure granulocytes from normal donors or with a whole leukocyte suspension obtained from a chronic myelogenous leukemia (CML) patient, and then fusing the mouse spleen cells with a 315–43 myeloma cell clone. Four MCA were selected and studied using ELISA, immunofluorescence, cytotoxicity assays, and FACS analysis. Antibodies 80H.1. 80H.3. and 80H.5 (from normals) and 81H.1 (from CML) detected antigens expressed on neutrophils. Antibodies 80H.1 and 80H.3 (lgG) also reacted with monocytes but not with other blood cell subsets. Antibodies 80H.5 and 81H.1 (lgM) were cytotoxic and reacted strongly with most of the cells of the neutrophil maturation sequence. i.e., myeloblasts, promyelocytes, myelocytes, and mature granulocytes. Antibodies 80H.5 and 81H.1 also inhibited BFU-GM and CFU-E. Antigens recognized by 80H.3. 80H.5, and 81H.1 were expressed both on a proportion of cells from HL.60, KG.1, ML.1, and K562 myeloid cell lines, and on a proportion of blast cells isolated from patients with acute myelogenous leukemia. They were not found on lymphoid cell lines or lymphoid leukemia cells. These MCA recognize either late differentiation antigens expressed on mature neutrophils and monocytes (80H.1 and 80H.3) or early differentiation antigens (80H.5 and 81H.1) specific to the granulocytic lineage. They may be useful for a better definition of those antigens specific to hematopoietic stem cells and their relationship with normal or neoplastic hematopoiesis. 相似文献
38.
Jacqueline T. Hecht Nora M. Thompson Tempa Weir Larry Patchell William A. Horton 《American journal of medical genetics. Part A》1991,41(2):208-211
Thirteen infants with achondroplasia underwent psychometric testing as part of a comprehensive neurologic assessment. As a group, mental development was average and motor development was delayed, although a wide range of scores was obtained. Foramen magnum measurements were correlated with respiratory dysfunction, abnormal so-matosensory evoked potentials, and delayed motor development. Abnormal polysomno-gram outcome was associated with reduced mental capacity. In light of the reported increased frequency of respiratory dysfunction in achondroplasia, these findings warrant careful attention and further study. 相似文献
39.
Seeliger F Drögemüller C Tegtmeier P Baumgärtner W Distl O Leeb T 《Journal of comparative pathology》2005,132(4):346-349
A 2-year-old German Holstein bull was identified as a carrier of a mutation within the X-chromosomal ED1 gene, which encodes a TNF-related signalling molecule mainly involved in ectodermal development. The clinicopathological appearance was associated with hypotrichosis, hypodontia, and a reduced number of eccrine glands, in addition to chronic rhinotracheitis and partial squamous metaplasia. Furthermore, for the first time in an ED1-deficient animal, a complete lack of respiratory mucous glands was observed. This suggests that the ED1 gene plays a role in the development of mucous glands, the absence of which resembles a feature of X-linked anhidrotic ectodermal dysplasia (ED1) in human patients. 相似文献
40.
In this study, the relationship between physiological arousal, as indexed by heart rate variability, was examined in boys with fragile X syndrome (FXS) and typically developing boys matched on chronological age. In addition, the relationship of heart activity to clinical and molecular factors in the group of boys with FXS was examined. Results suggest that boys with FXS have higher levels of heart activity during the passive phases, as reflected in shorter heart periods. This high level of heart activity appears to be due to increased sympathetic activity and reduced parasympathetic activity. Boys with FXS did not display the expected patterns of heart activity in response to phases of increasing challenge, and sympathetic and parasympathetic systems did not appear coordinated in these boys with FXS. Clinical factors may be related to neural regulation of heart activity while molecular factors do not appear to be. 相似文献